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Pumper for 98 400

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Hey everyone I'm thinking about going to a mikuni pumper. do you guys know what all has to be manufactured as far as adapters if i "came accross" one that was just the carb.

and I know XR's only has the kit, do you know if this would fit just from roughly what the specs are saying

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=320287302954&_trksid=p2759.l1259

Also what kind of power increase do these things typically provide? i'm running basically stock except snorkel removed and 416cc at 10.8:1

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Your going to get better throttle response. Not so much in power gain.

To get more power you have to put more into cylinder so if the carb is larger then at wide open yes you would get a little more air into the motor and assuming your have it all jetted right (air to fuel ratio at that opening) then yes a gain. But you also need to consider other factors on air flow to gain power. Air filter and its restrictions, Exhaust restrictions, Cam (longer duration and or opening valves more).

I think the consensus from those that have pumpers are that they remove the hesitation and make it just run so much better.

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I have the pumper carb on two xr 400's.One 440,and a stocker exlint Big power gains.With the right mods to air box and change the pipe and muffler

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i got mine from XR's Only. had to tweak it a bit (mainly air screw) and she runs great. huge improvement from stock.

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Just put a new Mikuni on my XR yesterday, and it's a different bike. Unbelievable. Got it from XR's Only, good price and service. You won't be sorry for doing it, even if that's all you do.:worthy:👍

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Just put one 2 days ago ( Aug 20th ) on my XR400R (440) .

Day and night.

Twist the throttle and the motor revs like never , no hesitation and on cold start , just twist the throttle twice , pull the choke and it will start 1st kit .

I practice starting the bike 3 times a day ( when the bike is cold ) and with this method , it will start 1st kick everytime.

I love it. 👍

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everything i have heard about pumper carbs is good are there any down sides to the new carb?

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